Month: December 2006

Hack-A-Day friend [Limor] AKA [ladyada] has been promising a portable RF jammer for a while. guess what she sent me for Christmas? The Wave-bubble is a self tuning RF jammer – good for around 20 feet of RF enforced peace. (It outputs .1-.3 watts) With a pair of less efficient antennas, it even fits inside a pack of cigarettes. She’ll never sell these because the FCC would come-a-knockin, but if you’ve got some major skills, you might be able to build one. (I’m going to believe her take on this, I’ve seen her work in person and it’s some damn fine stuff)

We all remember the diy cnc laser. In my quest to bring you guys fresh stuff, I found an interesting design [archived page](the author says he built his in the 80s) for a home-built CO2 laser. The dimensions are missing, but the design is pretty simple. If you like some textbook style reading, the hyperphysics server is your friend. I finally bought a mini mill to go with my lathe – this could make an interesting machining project. Get a mini-fridge compressor to for the vacuum source, and the gas is easily acquired from the local welding shop. I’d bet Surplus shed probably has some workable optics.

The 25th is the deadline for the Design Challenge. Don’t freak out, just get it submitted before I get up on the 26th, and I’ll call it good.

Remember this? We hit it last year. [William] has been working hard, and made plenty of improvements. Aside from building it in black, he’s built a new model. He’s even hoping to release it as a kit in 2007. The latest version uses a PIC to fire the coils and manages the batteries, uses a pair of IR sensors to time the projectile, laser sighting and improved charging. It’s still only slightly more powerful than a CO2 BB gun, but one hell of an engineering challenge. Theoretically, these could be more powerful than traditional firearms, but power limitations keep them repressed like mid-evil peasants.

[Jan] noted that they’ve come up with an interesting, low cost method of 3d scanning over (Update: http://www.david-laserscanner.com/wiki) at the Institute for Robotics and Process Control. Once the software is calibrated with the preset background image, a laser line is run over the object (Just think about every sci-fi laser scanner you’ve ever seen) The software appears to measure the contour of the object by the breaks in the line as it’s passed over the object. Once a mesh of measurements is taken, the object can be reconstructed in the software. According to [Jan] “With Their technique they won the Main Prize of the “work group for Pattern recognition” this Year in Berlin.” Now, make it work under something besides windows and .NET.

Just a quick note – my How-To on building your own MP3 player is up. It’s more of a build walk-through and a review of MAKE’s Daisy MP3 player kit.

In case you missed it, Ben Heck put up a How-to on making your own robotic hand. It’s more of an exercise in CAD design with the intent to cut the parts on a CNC machine. It’s a great view into Ben’s workflow. He used to torture er train graphic artists at some point, and he puts that experience to work in his designs. Speaking of which, you might dig his SCART video switcher.

I’ve got to say that I’m impressed with the effort I’ve seen so far on the Design Challenge. You’ve got five more days to get em in.

Before I forget, I need a good supplier of teflon/ptfe insulated wire (at a decent price). Suggestions?